Fuel Pump

[TT Paul]

Just fitted a new battery last night started the car up afterwards no problem, half an hour later went to start the car no fuel pump buzzing or fuel guage working. So i checked all the fuses and relays etc nothing suspect there, checked the inertia switch no probs there, i then put a wire to the fuel pump from positive source, fuel pump buzzing, car starts fine and got me home. question is how do i check or reset the immobiliser, the light on the dash has never worked since i bought the car, so can't tell if its on or off. The car is a 4.0 93 model

[spend]

Disturbed ECU plug connections?

Check Fuel pump relay with voltmeter - is it control or load circuit?

[TT Paul]

Ive had the ecu out now to check under dash also swapped relay with the one on same loom,(metal ones) how do i check for control or load circuit

[spend]

IIRC fuel pump supply is from ECU via fuse to relay (yellow wire on mine) and relay (when closed) to Inertia switch (yellow/black on mine) and then to fuel pump (yellow on mine).

The circuit which controls the relay is probably different on cars due to alarm/immob. Mine has 12v on one terminal and the alarm switches the earth on the other terminal - but I dont have original alarm....

Check you get 12v on the yellow wire to relay.

Check continuity from yellow black on relay to fuel pump.

If these are good its probably your immob. defeating the relay.

But id guess you've disturbed something or not reset the alarm correctly, could try reconnecting the battery or locking / unlocking...

[TT Paul]

Thanks for info, ive checked continuity (Yel) from pump to inertia ok, black and yel from inertia to black box under dash which controls central locking etc, continuity ok. yel to black box with ignition on 12v for 3 seconds to prime pump ok, but it wont switch to power yellow black to inertia. is this telling me the black box is faulty, does this also work in conjuction with fuel gauge, or does the immobilser seperatly power the black box to activate the switching coil inside

[spend]

Umm, The connection from the inertia switch goes to the fuel relay on mine. The connection from the CDL black box controls the relay (providing an earth)

Still sounds a like connection to ECU pin16 to me - check against p84 in the bible.

[k4trv]

TT Paul said:

Just fitted a new battery last night started the car up afterwards no problem, half an hour later went to start the car no fuel pump buzzing or fuel guage working. So i checked all the fuses and relays etc nothing suspect there, checked the inertia switch no probs there, i then put a wire to the fuel pump from positive source, fuel pump buzzing, car starts fine and got me home. question is how do i check or reset the immobiliser, the light on the dash has never worked since i bought the car, so can't tell if its on or off. The car is a 4.0 93 model

Hi,

I have an early '93 4.0. You will need to lock/unlock one of the doors to re-set the alarm immobliser, unless you have a remote key fob - doubt that with '93 model !! Have a look in the handbook for the "technique".


Without the red-LED on panel to tell you, it's a case of put key in door and lock, remove key & pause for 10 secs or so, then re-insert key and unlock door. Key in ignition and listen for buzzing fuel pump. This is only way to tell immoblisher is switched off (and fuel gauge !!). I found META alarm had been changed/butchered to a Clifford, but remote capability "removed" & no conection to dash LED - I reconnected, so at least I can tell when alarm is now on !!
Trev McM

[TT Paul]

Thanks for all your help, took it to auto electrician today and it turned out to be a dodgy immobiliser

Thanks again Paul